1. Field of the Invention
The present invention relates to a heat supply system which supplies an exhaust heat of a power generating equipment employing a fossil fuel or a heat generated by directly burning the fossil fuel to a commercial building, a factory, a house or the like (hereinafter, refer to a customer) and obtains a price.
2. Description of Prior Art
In a conventional heat supply system, the heat is supplied to the customer in the form of a vapor or a hot water, and the price is calculated in correspondence to an amount of the vapor or the hot water.
In this case, an application of the heat is different in the kind of the customer, that is, there are various cases including a case of a chemical process or the like requiring a high temperature, a case of a food sterilization requiring a heat about 100xc2x0 C., and a case of a heating or the like requiring a heat about some tens xc2x0 C. Further, there is a customer requiring the vapor or the hot water corresponding to the heat medium itself in addition to the heat, however, there is a customer requiring only the heat within a certain temperature range and requiring no heat medium having a lower temperature than the certain temperature range for the reason of the heat usage. In the case of the vapor, there is a case that a high pressure is required in addition to the temperature, however, there is a customer that can not use the medium having the reduced pressure due to the use even when the medium has a certain high level temperature. In this case, in accordance with the conventional system, the heat medium which does not reach the necessary pressure or temperature range is wasted in a state that an energy is not effectively utilized.
Further, although an expensive equipment is required for the purpose of producing the vapor having a high temperature and a high pressure so as to supply to the customer, an equipment for producing low-temperature hot water is not so expensive. However, in the system for supplying the vapor to the customer requiring the vapor having the high temperature or the high temperature and high pressure, the heat having an overvalued cost is also supplied to the customer requiring only the heat having a low temperature. If a unit price per an amount of heat is set to be the same as that of the customer requiring the high temperature and high pressure, the customer requiring only the low temperature heat buys the overvalued heat, and conversely, if the heat having the low temperature is set to be inexpensive, it is disadvantageous to recover the equipment.
An object of the present invention is to provide a heat supply system which is preferable for effectively utilizing an energy and supplying heat having a more inexpensive cost to a customer requiring various kinds of temperatures and pressures.
The object mentioned above can be achieved by recovering a heat medium after being used by a customer requiring heat having a high temperature range so as to use as a heat source for supplying a heat to a customer requiring a heat having a lower temperature range, and calculating a unit price of an amount of heat by a temperature and an amount of flow.
In this case, with respect to the customer recovering the heat medium, the unit price of the amount of heat is set to be higher in accordance that an arithmetic average between a specific enthalpy (h) of the heat medium supplied to the customer and a specific enthalpy (hL) of the medium discharged from the customer is higher, and with respect to the customer recovering no heat medium, the unit price of the amount of heat is set to be higher in accordance that an arithmetic average between a specific enthalpy (h) of the heat medium supplied to the customer and a specific enthalpy (hO) of the medium at normal temperature and normal pressure is higher.